Evolution (Evolution)

by David Turell , Tuesday, January 27, 2009, 14:29 (5560 days ago) @ George Jelliss

This article discusses possible causes of the Cambrian explosion
 
> http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&... 
> Nicholas Butterfield thinks that the appearance of sex and predation and multicellularity led to increased competition.
 
Good article. I had not seen the theory that preceding snowball earth events might have caused (in some way) The Cambrian Explosion. Snowball events are widely accepted. Butterfield's conjectures that sex led to more competition by providing more complex organisms to compete with is clearly a valid point. Just the appearance of sex is a huge jump in evolution. Bruce Runnegar's comment is certainly to the point: [ He is] "director of the Center for Astrobiology at UCLA and an expert on the fossil record at the Cambrian threshold, [he]says that Butterfield's argument, that ecological complexity in and of itself fueled further complexity, is a hard hypothesis to disagree with, but how would you test it? We don't understand the phenomenon well enough to have one unique explanation." - The moral still is: Darwinian just-so stories don't advance understanding at all. One cannot look at morphology and truly understand how it got that way. If we only could get at the DNA of those Cambrian fossils. - One other exact note: The Cambrian produced 36 of the current 37 animal families. However, that came from diverse forms that numbered close to 100.